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1.
Diabetes Obes Metab ; 25(4): 1011-1023, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36527386

RESUMEN

AIM: To report two phase I studies of the novel subcutaneous glucagon-like peptide-1 receptor/glucagon receptor (GLP-1R/GCGR) dual agonist BI 456906 versus placebo in healthy volunteers and people with overweight/obesity. MATERIALS AND METHODS: A phase Ia study (NCT03175211) investigated single rising doses (SRDs) of BI 456906 in 24 males with a body mass index (BMI) of 20-<30 kg/m2 . A phase Ib study (NCT03591718) investigated multiple rising doses (MRDs) of BI 456906 (escalated over 6 [Part A] or 16 [Part B] weeks) in 125 adults with a BMI of 27-40 kg/m2 . RESULTS: In the SRD study (N = 24), mean body weight decreased with increasing BI 456906 dose. In the MRD study, the maximum decreases in placebo-corrected mean body weight were at week 6 (-5.79%, dosage schedule [DS] 1; Part A) and week 16 (-13.8%, DS7; Part B). BI 456906 reduced plasma amino acids and glucagon, indicating target engagement at GCGRs and GLP-1Rs. Drug-related adverse events (AEs) increased with BI 456906 dose. The most frequent drug-related AE with SRDs was decreased appetite (n = 9, 50.0%), and two subjects (8.3%) did not complete the trial because of AEs (nausea and vomiting). During MRD Part A (N = 80), 10 subjects (12.5%) discontinued BI 456906, most commonly because of a cardiac or vascular AE (n = 6, 7.5%); during Part B (N = 45), eight subjects (17.8%) discontinued BI 456906, mainly because of AEs (n = 6, 13.3%), most commonly gastrointestinal disorders. CONCLUSIONS: BI 456906 produced a placebo-corrected body weight loss of 13.8% (week 16), highlighting its potential to promote clinically meaningful body weight loss in people with overweight/obesity.


Asunto(s)
Diabetes Mellitus Tipo 2 , Péptido 1 Similar al Glucagón , Adulto , Masculino , Humanos , Péptido 1 Similar al Glucagón/uso terapéutico , Hipoglucemiantes/uso terapéutico , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Receptores de Glucagón/agonistas , Receptor del Péptido 1 Similar al Glucagón/agonistas , Sobrepeso/tratamiento farmacológico , Glucemia/metabolismo , Peso Corporal , Obesidad/tratamiento farmacológico , Pérdida de Peso , Método Doble Ciego
2.
Xenobiotica ; 45(6): 520-9, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-25547626

RESUMEN

1. The absorption, biotransformation and excretion of empagliflozin, an SGLT2 inhibitor, were evaluated in eight healthy subjects following a single 50 mg oral dose of empagliflozin containing ∼100 µCi [(14)C]-empagliflozin. 2. Radioactivity was rapidly absorbed, with plasma levels peaking 1 h post-dose. Total exposure was lower in blood versus plasma, consistent with moderate (28.6-36.8%) red blood cell partitioning. Protein binding was 80.3-86.2%. 3. Most of the radioactive dose was recovered in urine (54.4%) and faeces (41.1%). Unchanged empagliflozin was the most abundant drug-related component in plasma, representing 75.5-77.4% of plasma radioactivity and 79.6% plasma radioactivity AUC0-12 h. Unchanged empagliflozin was the most abundant drug-related component in urine and faeces, representing 43.5% (23.7% of dose) and 82.9% (34.1% of dose) of radioactivity in urine and faeces, respectively. Six metabolites were identified in plasma: three glucuronide conjugates representing 4.7-7.1% of AUC0-12 h and three less abundant metabolites (<0.2-1.9% AUC0-12 h). The most abundant metabolites in urine were two glucuronide conjugates (7.8-13.2% of dose) and in faeces was a tetrahydrofuran ring-opened carboxylic acid metabolite (1.9% of dose). 4. To conclude, empagliflozin was rapidly absorbed and excreted primarily unchanged in urine and faeces. Unchanged parent was the major drug-related component in plasma. Metabolism was primarily via glucuronide conjugation.


Asunto(s)
Compuestos de Bencidrilo/administración & dosificación , Compuestos de Bencidrilo/farmacocinética , Glucósidos/administración & dosificación , Glucósidos/farmacocinética , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Adolescente , Adulto , Humanos , Masculino , Persona de Mediana Edad , Transportador 2 de Sodio-Glucosa
3.
Int J Clin Pharmacol Ther ; 52(7): 549-63, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-24755124

RESUMEN

OBJECTIVE: The objectives of the studies reported here were to determine the relative bioavailability of linagliptin and metformin when administered in a fixed-dose combination (FDC) tablet with and without food, and to investigate the relative bioavailability of linagliptin and metformin FDC tablets from two treatment batches with different dissolution behavior. METHODS: These studies were open-label, single-dose, randomized, two-way crossover trials. After an overnight fast, healthy volunteers received an FDC tablet once (with/without food in the food-effect study; or from one of two batches with differing dissolution behavior in the tablet-dissolution study). On a separate visit, following a washout period of 35 days, participants received the alternative treatment. In the food-effect study the primary endpoints were maximum measured concentration in plasma (C(max)) for linagliptin and metformin, area under the plasma concentration-time curve from 0 to 72 hours (AUC(0-72)) for linagliptin and from 0 to infinity (AUC(0-inf)) for metformin. In the tablet-dissolution study the primary endpoints were Cmax for both analytes, AUC(0-72) for linagliptin, and from 0 to the time of the last quantifiable data point (AUC(0-t)) for metformin. RESULTS: The administration of the FDC tablet with food had no influence on the relative bioavailability of linagliptin and metformin with regard to the extent of exposure as determined by AUC(0-72) (linagliptin) and AUC(0-inf) (metformin) compared with FDC tablet administration while fasting. After food intake, peak plasma concentrations of linagliptin were slightly lowered (from 4.99 to 4.56 nmol L⁻¹), but the 90% confidence interval (CI) of the geometric mean test/reference ratio was still located within the generally applied bioequivalence acceptance limits of 80 - 125%. The median time from dosing to the maximum concentration of linagliptin in plasma (t(max)) was similar under both conditions. Administration with food reduced the rate of absorption of metformin indicated by a prolongation in median tmax (from 2 to 4 hours) and a decrease in Cmax by ~ 18%. There were no notable differences between the two treatment groups with respect to safety and tolerability. In the tablet-dissolution study, bioequivalence was demonstrated between linagliptin/metformin FDC tablets with normal and slower dissolution characteristics. For both linagliptin and metformin, the 90% CI of all pharmacokinetic (PK) parameters were well within the bioequivalence acceptance limits of 80 - 125%. Tablets from both batches were well tolerated with no unexpected adverse events. CONCLUSIONS: Food did not have a relevant impact on the bioavailability of linagliptin from the FDC tablet. The effect of food on the metformin component was comparable to that previously demonstrated. Furthermore, differences in tablet-dissolution characteristics did not have an impact on the bioavailability of linagliptin or metformin from the FDC tablet.


Asunto(s)
Interacciones Alimento-Droga , Hipoglucemiantes/administración & dosificación , Metformina/administración & dosificación , Purinas/administración & dosificación , Quinazolinas/administración & dosificación , Adulto , Área Bajo la Curva , Disponibilidad Biológica , Estudios Cruzados , Combinación de Medicamentos , Femenino , Humanos , Linagliptina , Masculino , Metformina/efectos adversos , Metformina/química , Metformina/farmacocinética , Persona de Mediana Edad , Purinas/efectos adversos , Purinas/química , Purinas/farmacocinética , Quinazolinas/efectos adversos , Quinazolinas/química , Quinazolinas/farmacocinética , Solubilidad , Comprimidos
4.
Int J Clin Pharmacol Ther ; 51(11): 873-9, 2013 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-24152604

RESUMEN

OBJECTIVES: Empagliflozin is an orally available, potent and highly selective inhibitor of the sodium glucose cotransporter 2 (SGLT2). This study was undertaken to investigate the effect of food on the pharmacokinetics of 25 mg empagliflozin and to assess dose proportionality between 10 mg and 25 mg empagliflozin under fasted conditions. MATERIALS AND METHODS: In this open-label, 3-way, cross-over study, 18 healthy volunteers received 3 single doses of empagliflozin in a randomized sequence (25 mg empagliflozin under fasted conditions, 25 mg empagliflozin after a high-fat, high-calorie breakfast and 10 mg empagliflozin under fasted conditions), each separated by a washout period of at least 7 days. Serial plasma samples were collected at selected time points over a period of 72 hours. RESULTS: Administration with food had no clinically relevant effect on the area under the plasma concentration-time curve (AUC0-∞) of empagliflozin (geometric mean ratio (GMR): 84.04, 90% confidence interval (CI): 80.86 - 87.34). The decrease observed in the maximum plasma concentrations (Cmax) of empagliflozin (GMR: 63.22, 90% CI: 56.74 - 70.44) when administered with food was not considered clinically meaningful. The increases in AUC0-∞ and Cmax for 10 mg vs. 25 mg empagliflozin administered under fasting conditions were roughly dose-proportional, as demonstrated by the slope ß of the regression lines being slightly less than 1 (slope ß for AUC0-∞: 0.94, 95% CI: 0.90 - 0.97; slope ß for Cmax: 0.91, 95% CI: 0.80 - 1.01). Empagliflozin was well tolerated under fed and fasting conditions. CONCLUSIONS: The results support administration of empagliflozin tablets independently of food. Increases in empagliflozin exposure under fasting conditions were roughly dose-proportional between 10 mg and 25 mg empagliflozin.


Asunto(s)
Compuestos de Bencidrilo/farmacocinética , Interacciones Alimento-Droga , Glucósidos/farmacocinética , Inhibidores del Cotransportador de Sodio-Glucosa 2 , Adulto , Área Bajo la Curva , Compuestos de Bencidrilo/administración & dosificación , Compuestos de Bencidrilo/efectos adversos , Estudios Cruzados , Femenino , Glucósidos/administración & dosificación , Glucósidos/efectos adversos , Voluntarios Sanos , Humanos , Masculino , Persona de Mediana Edad , Transportador 2 de Sodio-Glucosa , Adulto Joven
5.
Clin Diabetes Endocrinol ; 7(1): 16, 2021 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-34391480

RESUMEN

BACKGROUND: The study characterizes safety, tolerability, pharmacokinetic and pharmacodynamic profiles of single rising doses of the 11beta-hydroxysteroid dehydrogenase-1 (11beta-HSD1) inhibitor BI 187004 in healthy men with overweight or obesity. METHODS: This was a randomized, double-blind, parallel group, placebo-controlled study with administration of 2.5-360 mg BI 187004 or placebo once daily as single dose in 72 healthy male volunteers with overweight or obesity. Assessments included 11beta-HSD1 inhibition in the liver (assessed indirectly by urinary tetrahydrocortisol/tetrahydrocortisone ratio) and in subcutaneous adipose tissue ex vivo and determination of hypothalamus-pituitary-adrenal axis hormones. RESULTS: BI 187004 was well tolerated and safe in all tested dose groups. The incidence of drug-related adverse events was 16.7% (n = 9) for all 9 BI 187004 dose groups and 5.9% (n = 1) for placebo. All treatment groups were similar concerning kind and intensity of adverse events. No clinically relevant deviations in clinical laboratory or ECG parameters were reported. Exposure of BI 187004 increased non-proportionally over the entire dose range tested. The geometric mean apparent terminal half-life decreased from 33.5 h (5 mg) to 14.5 h (160 mg) remaining stable up to 360 mg. Renal excretion of BI 187004 was low (3-5%). Urinary tetrahydrocortisol/tetrahydrocortisone ratio decreased, indicating liver 11beta-HSD1 inhibition. Median inhibition of 11beta-HSD1 in subcutaneous adipose tissue biopsies following single dosing ranged from 86.8% (10 mg) to 99.5% (360 mg) after 10 h and from 59.4% (10 mg) to 98.6% (360 mg) after 24 h. CONCLUSIONS: BI 187004 as single dose was safe and well tolerated and is suitable for once daily dosing. There was significant, sustained 11beta-HSD1 inhibition in liver and adipose tissue. TRIAL REGISTRATION: ClinicalTrials.gov, NCT01587417 , registered on 26-Apr-2012.

6.
Eur J Drug Metab Pharmacokinet ; 43(5): 533-541, 2018 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-29500603

RESUMEN

BACKGROUND: Nintedanib is a substrate for p-glycoprotein which can impact bioavailability. We investigated the effects of ketoconazole, a p-glycoprotein inhibitor, and rifampicin, a p-glycoprotein inducer, on the pharmacokinetics of nintedanib. METHODS: In the ketoconazole study, 34 healthy subjects received nintedanib 50 mg orally alone and 1 h after the last dose of ketoconazole given orally at a dose of 400 mg once daily for 3 days in 1 of 2 randomized sequences. In the rifampicin study, 26 subjects received nintedanib 150 mg orally alone and the morning after the last dose of rifampicin given orally at a dose of 600 mg once daily for 7 days. The primary objective was to determine the relative bioavailability of nintedanib administered following multiple doses of ketoconazole or rifampicin versus alone, based on AUC from time 0 extrapolated to infinity (AUC0-∞) and maximum concentration (Cmax) calculated using an analysis of variance. Geometric mean ratios and 2-sided 90% CIs were calculated. RESULTS: Exposure to nintedanib increased when it was administered following ketoconazole versus alone (AUC0-∞: geometric mean ratio, 160.5% [90% CI, 148.2-173.7]; Cmax: geometric mean ratio, 179.6% [90% CI, 157.6-204.8]) and decreased when it was administered following rifampicin versus alone (AUC0-∞: geometric mean ratio, 50.1% [90% CI, 47.2-53.3]; Cmax: geometric mean ratio, 59.8% [90% CI, 53.8-66.4]). The time to reach Cmax (tmax) and half-life (t½) of nintedanib were unaffected by co-administration of ketoconazole or rifampicin. CONCLUSIONS: Exposure to nintedanib is increased by co-administration of ketoconazole and decreased by co-administration of rifampicin, likely due to effects on bioavailability of the absorbed fraction. ClinicalTrials.govidentifiers:NCT01679613, NCT01770392.


Asunto(s)
Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Indoles/administración & dosificación , Indoles/farmacocinética , Cetoconazol/administración & dosificación , Rifampin/administración & dosificación , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/agonistas , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/antagonistas & inhibidores , Administración Oral , Adolescente , Adulto , Disponibilidad Biológica , Estudios Cruzados , Esquema de Medicación , Interacciones Farmacológicas , Alemania , Voluntarios Sanos , Humanos , Indoles/efectos adversos , Absorción Intestinal , Cetoconazol/efectos adversos , Masculino , Persona de Mediana Edad , Modelos Biológicos , Rifampin/efectos adversos , Medición de Riesgo , Adulto Joven
7.
Eur J Drug Metab Pharmacokinet ; 43(1): 69-80, 2018 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28685495

RESUMEN

BACKGROUND: In a recently described probe drug cocktail for clinically relevant drug transporters containing digoxin, furosemide, metformin and rosuvastatin, mutual interactions were essentially absent except for increases in the systemic exposure of rosuvastatin. To optimize the cocktail, we further examined the dose dependence of the effects of metformin and furosemide on rosuvastatin pharmacokinetics. METHODS: This was a randomized, open label, single center, six-treatment, six-period, six-sequence crossover trial. Eighteen healthy male subjects received 10 mg rosuvastatin as reference treatment and, as test treatments, 10 mg rosuvastatin combined with 10, 50 or 500 mg metformin (T1, T2 and T3) or with 1 or 5 mg furosemide (T4 and T5). Primary pharmacokinetic endpoints were rosuvastatin C max (maximum plasma concentration) and AUC0-tz (area under the plasma concentration-time curve from time zero to the last quantifiable concentration). RESULTS: The relative bioavailability of rosuvastatin was essentially unchanged when administered with metformin in T1 and T2, but in T3 it increased to 152% for AUC0-tz (90% CI 135-171%) and 154% for C max (90% CI 132-180%). Coadministration with furosemide did not change rosuvastatin relative bioavailability in T4, but in T5 it increased slightly to 116% for AUC0-tz (90% CI 102-132%) and 118% for C max (90% CI 98-142%). CONCLUSION: The increased systemic exposure of rosuvastatin when administered as part of the proposed transporter cocktail is most likely attributable to metformin and only to a minor degree to furosemide. Reduction of the doses of metformin and furosemide is expected to eliminate the previously described interaction. EudraCT no. 2015-003052-46, ClinicalTrials.gov identifier NCT02574845.


Asunto(s)
Furosemida/farmacología , Metformina/farmacología , Rosuvastatina Cálcica/farmacocinética , Adolescente , Adulto , Anticolesterolemiantes/sangre , Anticolesterolemiantes/farmacocinética , Disponibilidad Biológica , Estudios Cruzados , Diuréticos/farmacología , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Voluntarios Sanos , Humanos , Hipoglucemiantes/farmacología , Masculino , Persona de Mediana Edad , Rosuvastatina Cálcica/sangre , Adulto Joven
8.
Clin Pharmacol Ther ; 80(3): 246-56, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16952491

RESUMEN

OBJECTIVE: In patients with renal disease increased urotensin II plasma levels have been observed. We have investigated whether palosuran, a potent, selective, and competitive antagonist of the urotensin II receptor, has effects in patients who are prone to the development of renal disease. METHODS: Macroalbuminuric, diabetic patients, categorized by renal function, were treated with oral doses of 125 mg palosuran twice daily for 13.5 days in addition to treatment with either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. The 24-hour urinary albumin excretion rate was determined twice at baseline and after 13.5 days of treatment. Plasma concentrations of palosuran were determined for 12 hours after the first and last drug intake. Renal hemodynamics was measured before and after 12.5 days of treatment. Tolerability and safety parameters were monitored. RESULTS: An overall clinically significant reduction of 24.3% (geometric mean) (95% confidence interval, 4.1 to 45.0) in the 24-hour urinary albumin excretion rate was observed (P = .014). No effect was observed on renal hemodynamic parameters. Palosuran was rapidly absorbed with maximum plasma concentrations at 1 hour after drug administration. The accumulation factor was 1.7 (geometric mean) (95% confidence interval, 1.3 to 2.1). Palosuran was well tolerated. CONCLUSIONS: The good tolerability profile and the decrease in the 24-hour urinary albumin excretion rate may benefit diabetic patients with renal failure with regard to their disease progression. Larger placebo-controlled trials in this patient population are needed to investigate whether urotensin II receptor antagonists, given as monotherapy or combination therapy, may improve the current treatment of diabetic nephropathy.


Asunto(s)
Albuminuria/prevención & control , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Quinolinas/farmacocinética , Receptores Acoplados a Proteínas G/antagonistas & inhibidores , Urea/análogos & derivados , Anciano , Albuminuria/tratamiento farmacológico , Bloqueadores del Receptor Tipo 1 de Angiotensina II/uso terapéutico , Inhibidores de la Enzima Convertidora de Angiotensina/uso terapéutico , Área Bajo la Curva , Creatinina/sangre , Creatinina/orina , Diabetes Mellitus Tipo 2/complicaciones , Nefropatías Diabéticas/complicaciones , Nefropatías Diabéticas/tratamiento farmacológico , Fatiga/inducido químicamente , Femenino , Tasa de Filtración Glomerular/efectos de los fármacos , Cefalea/inducido químicamente , Humanos , Hipertensión/complicaciones , Hipertensión/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Nasofaringitis/inducido químicamente , Quinolinas/efectos adversos , Quinolinas/uso terapéutico , Circulación Renal/efectos de los fármacos , Resultado del Tratamiento , Urea/efectos adversos , Urea/farmacocinética , Urea/uso terapéutico
9.
Clin Drug Investig ; 34(3): 173-82, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24399452

RESUMEN

BACKGROUND AND OBJECTIVE: Afatinib is a potent, irreversible, ErbB family blocker in clinical development for the treatment of advanced non-small cell lung cancer, metastatic head and neck cancer, and other solid tumours. As afatinib is a substrate for the P-glycoprotein (P-gp) pump transporter the three studies presented here investigated the pharmacokinetics of afatinib in the presence of a potent inhibitor (ritonavir) or inducer [rifampicin (rifampin)] of P-gp. METHODS: We conducted phase I, open-label, single-centre studies in healthy male volunteers who received a single once-daily oral dose of afatinib (20 or 40 mg) together with either ritonavir or rifampicin; two studies had a randomised, two- and three-way crossover design and the third was a non-randomised, two-period sequential study. RESULTS: When afatinib 20 mg was administered 1 h after ritonavir, afatinib geometric mean (gMean) maximum plasma concentration (C max) and area under the plasma concentration-time curve from time zero to infinity (AUC∞) increased by 38.5 and 47.6 %, respectively. Coadministration of ritonavir either simultaneously or 6 h later than afatinib 40 mg resulted in minimal increase in the afatinib gMean C max and AUC∞ (4.1 and 18.6 % for simultaneous administration with AUC∞ not completely within the bioequivalence limits; 5.1 and 10.8 % for timed administration within the bioequivalence limits). Administration of afatinib 40 mg in the presence of rifampicin led to reduction in C max and AUC∞ by 21.6 and 33.8 %, respectively. In all studies, P-gp modulation mainly affected the extent of absorption of afatinib; there was no change in the terminal elimination half-life. The overall safety profile of afatinib was acceptable. CONCLUSION: Coadministration of potent P-gp modulators had no clinically relevant effect on afatinib exposure. Effects of potent P-gp inhibitors were minimal at higher afatinib doses and can be readily managed by the timing of concomitant therapy. As afatinib is not a relevant modulator or substrate of cytochrome P450 enzymes, the drug-drug interaction potential is considered to be low.


Asunto(s)
Quinazolinas/farmacocinética , Rifampin/farmacocinética , Ritonavir/farmacocinética , Adolescente , Adulto , Afatinib , Estudios Cruzados , Combinación de Medicamentos , Interacciones Farmacológicas/fisiología , Humanos , Masculino , Persona de Mediana Edad , Quinazolinas/administración & dosificación , Rifampin/administración & dosificación , Ritonavir/administración & dosificación , Adulto Joven
10.
Clin Pharmacokinet ; 49(12): 829-40, 2010 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21053992

RESUMEN

BACKGROUND AND OBJECTIVES: Linagliptin (BI 1356) is a highly specific inhibitor of dipeptidyl peptidase (DPP)-4, which is currently in phase III clinical development for the treatment of type 2 diabetes mellitus. Linagliptin exhibits nonlinear pharmacokinetics after oral administration, which are mainly related to concentration-dependent binding of linagliptin to its target, DPP-4. The objectives of the study were to investigate the pharmacokinetics and pharmacodynamics after intravenous administration of linagliptin and to determine its absolute bioavailability (F). SUBJECTS AND METHODS: This was a single rising-dose, randomized, four-group, placebo-controlled, single-blind (within dose groups) study. Thirty-six healthy men aged 18-50 years were enrolled and randomized into four sequential treatment groups. Group 1 received linagliptin 0.5 mg intravenously, group 2 received 2.5 mg intravenously and group 4 received 10 mg intravenously. In group 3, subjects underwent a two-way randomized crossover, receiving 5 mg intravenously and a 10 mg oral tablet. Linagliptin concentrations in plasma and urine, as well as plasma DPP-4 activity, were determined by validated assays. Noncompartmental analysis and population pharmacokinetic modelling were performed. RESULTS: Linagliptin showed nonlinear pharmacokinetics after intravenous infusion of 0.5-10 mg, with a less than dose-proportional increase in exposure. Noncompartmental parameters were calculated on the basis of total (i.e. bound and unbound) plasma concentrations. The total clearance value was low and increased with dose from 2.51 to 14.3 L/h. The apparent steady-state volume of distribution (V(ss)) increased with dose from 380 to 1540 L. Renal excretion of the unchanged parent compound increased with increasing plasma concentrations from 2.72% in the 0.5 mg dose group to 23.0% in the 10 mg dose group. The terminal elimination half-life was comparable across dose groups (126-139 hours). Because of the nonlinear pharmacokinetics, the standard approach of comparing the area under the plasma concentration-time curve (AUC) after oral administration with the AUC after intravenous administration led to dose-dependent estimates of the absolute bioavailability. Therefore, a population pharmacokinetic model was developed, accounting for the concentration-dependent protein binding of linagliptin to its target enzyme, DPP-4. The model-derived estimates of the V(ss) and clearance of linagliptin not bound to DPP-4 were 402.2 L and 26.9 L/h, respectively. The absolute bioavailability was estimated to be about 30% for the linagliptin 10 mg tablet. CONCLUSION: The nonlinear pharmacokinetic characteristics and the pharmacokinetic/pharmacodynamic relationship of linagliptin were independent of the mode of administration (intravenous or oral). Because of the nonlinear pharmacokinetics, the standard approach of comparing the AUC after oral administration with the AUC after intravenous administration was inappropriate to determine the absolute bioavailability of linagliptin. By a modelling approach, the absolute bioavailability of the 10 mg linagliptin tablet was estimated to be about 30%.


Asunto(s)
Inhibidores de la Dipeptidil-Peptidasa IV/farmacocinética , Modelos Biológicos , Purinas/farmacocinética , Quinazolinas/farmacocinética , Adolescente , Adulto , Área Bajo la Curva , Disponibilidad Biológica , Estudios Cruzados , Dipeptidil Peptidasa 4/metabolismo , Inhibidores de la Dipeptidil-Peptidasa IV/administración & dosificación , Inhibidores de la Dipeptidil-Peptidasa IV/metabolismo , Relación Dosis-Respuesta a Droga , Semivida , Humanos , Infusiones Intravenosas , Linagliptina , Masculino , Persona de Mediana Edad , Unión Proteica , Purinas/administración & dosificación , Purinas/metabolismo , Quinazolinas/administración & dosificación , Quinazolinas/metabolismo , Método Simple Ciego , Comprimidos , Distribución Tisular , Adulto Joven
11.
Antimicrob Agents Chemother ; 51(1): 103-9, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-17060516

RESUMEN

The pharmacokinetic profiles of azithromycin given as a single-dose regimen (2.0-g extended-release microspheres) were characterized in serum and white blood cells (WBC) and compared with those of a 3-day regimen (a 500-mg immediate-release tablet once daily; total dose, 1.5 g) in an open-label, randomized, parallel-group study of 24 healthy adult subjects. Serial blood samples were collected up to 5 days after the start of dosing for both regimens. Safety assessments were conducted throughout the study. A single 2.0-g dose of azithromycin microspheres achieved significantly higher exposures in serum and WBC during the first 24 h after the start of dosing than a 3-day regimen: an approximately threefold higher area under the curve from time zero to 24 h postdose (AUC(0-24)) and an approximately twofold higher mean peak concentration on day 1. The single-dose regimen provided total azithromycin exposures in serum and WBC similar to those of the 3-day regimen, as evidenced by the similar AUC(0-120) and trough azithromycin concentrations in serum and WBC (mononuclear leukocytes [MNL] and polymorphonuclear leukocytes [PMNL]). For both regimens, the average total azithromycin exposures in MNL and PMNL were approximately 300- and 600-fold higher than those in serum. Azithromycin concentrations in MNL and PMNL remained above 10 microg/ml for at least 5 days after the start of dosing for both regimens. This "front-loading" of the dose on day 1 is safely achieved by the extended-release microsphere formulation, which maximizes the drug exposure at the time when the bacterial burden is likely to be highest.


Asunto(s)
Antibacterianos/farmacocinética , Azitromicina/farmacocinética , Preparaciones de Acción Retardada/farmacocinética , Leucocitos/metabolismo , Suero/metabolismo , Adolescente , Adulto , Antibacterianos/administración & dosificación , Área Bajo la Curva , Azitromicina/administración & dosificación , Preparaciones de Acción Retardada/administración & dosificación , Femenino , Humanos , Leucocitos Mononucleares/metabolismo , Masculino , Neutrófilos/metabolismo
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